Singlet oxygen quantum yields from halogenated chlorins: potential new photodyn...

• Author(s): Pineiro, Marta ; Pereira, Mariette M. ; Rocha Gonsalves, A. M. d'A. ; Arnaut, Luis G. ; Formosinho, Sebastião J.
• Date: 2001
• Persistent ID: http://hdl.handle.net/10316/5228
• Origin: Estudo Geral - Universidade de Coimbra
• Subject(s): Photoacoustic calorimetry; Chlorin; Singlet oxygen; Sensitisers; Photodynamic therapy
• Document Type: Article
• Language: English

Description

Flash photolysis and photoacoustic calorimetry were used to measure the energy-transfer rates and singlet oxygen quantum yields originated by the triplet states of halogenated tetrakisphenylporphyrins and related chlorins in aerated toluene. The chlorins ([lambda]max[approximate]660 nm, [var epsilon][approximate]3×104 M-1 cm-1) have long-lived triplet states (>12 [mu]s) in the absence of molecular oxygen, and in its presence the singlet oxygen production quantum yields of the 2-chloro and 2,6-dichlorophenyl derivatives are 0.89±0.05 and 0.98±0.02, respectively. The high absorptivity in the red, the photostability and the efficiency of these chlorins in producing singlet oxygen suggests a ground for the development of better sensitisers for photodynamic therapy. http://www.sciencedirect.com/science/article/B6TGY-41YG70D-7/1/de6fc7896eaf9c58239551fa798e3e7b